Antimicrobial and Cytotoxic Activities of Selected Hieracium L. s. str. (Asteraceae) Extracts and Isolated Sesquiterpene Lactones

Abstract

Antimicrobial and cytotoxic activities were tested for dried MeOH extracts of Hieracium calophyllum (CAL), H. coloriscapum (COL), H. pseudoschenkii (PSE), H. valdepilosum (VAL) and H. glabratum (GLA) herbs (flowering aerial parts), their 2 sesquiterpene lactones (SLs) 8‐epiixerisamine A and crepiside E, and dried CH2Cl2 extract of H. scheppigianum (SCH) herb. In microdilution test, extracts showed activity on all tested microorganisms (8 bacteria, 10 fungi). The best effect was exhibited by SCH and CAL on Salmonella Typhimurium (MIC=1.7–2.5 mg/mL MBC=3.4–5.0 mg/mL), and SCH and VAL on Candida albicans (MIC=2.5 mg/mL MFC=5.0 mg/mL). SLs showed notable effect on all tested fungi Aspergillus ochraceus, Penicillium funiculosum, C. albicans and C. krusei (MIC=0.15–0.4 mg/mL MFC=0.3–0.8 mg/mL). In MTT test, extracts inhibited growth of all tested cancer cells (HeLa, LS174 and A549), with the best effect on HeLa (IC50=148.1 μg/mL for SCH, and 152.3–303.2 μg/mL for MeOH extracts); both SLs were active against HeLa cells (IC50=46.2 μg/mL for crepiside E and 103.8 μg/mL for 8‐epiixerisamine A). Extracts and SLs showed good safety profile on normal MRC‐5 cells.

Investigation of Anticholinesterase Activity of Chemically Characterised Hieracium s. str. Methanol Extracts and Their Selected Metabolites

“…The greatest species richness has been recorded in western, northern and central Europe, the Alps, and the western Balkan Peninsula especially in Mt Durmitor in Montenegro. Only about 1.5 % of the approximately 5000 members of this genus in the strict sense have been investigated so far for their chemical composition and/or pharmacological activities [8,9] . In most of the previous studies, the aerial parts of the plants were studied.…”

“…For example, we analysed phenolic acids, flavonoids and sesquiterpene lactones in the dried methanol (MeOH) extracts of the flowering aerial parts (herbs) of 28 Hieracium species (Table S1), the antioxidant activity of all these extracts, the antimicrobial and cytotoxic effects of five, and the antihyperalgesic and antiedematous activities of two extracts. [8,[10][11][12] As for the underground parts, only H. pannosum Boiss. has been previously studied (the phenolics content, antioxidant potential, and ability to inhibit α-glucosidase and α-amylase of the MeOH extract).…”

“…In most of the previous studies, the aerial parts of the plants were studied. For example, we analysed phenolic acids, flavonoids and sesquiterpene lactones in the dried methanol (MeOH) extracts of the flowering aerial parts (herbs) of 28 Hieracium species ( Table S1 ), the antioxidant activity of all these extracts, the antimicrobial and cytotoxic effects of five, and the antihyperalgesic and antiedematous activities of two extracts [8,10–12] . As for the underground parts, only H. pannosum Boiss.…”

“…Only about 1.5 % of the approximately 5000 members of this genus in the strict sense have been investigated so far for their chemical composition and/or pharmacological activities. [8,9] In most of the previous studies, the aerial parts of the plants were studied. For example, we analysed phenolic acids, flavonoids and sesquiterpene lactones in the dried methanol (MeOH) extracts of the flowering aerial parts (herbs) of 28 Hieracium species (Table S1), the antioxidant activity of all these extracts, the antimicrobial and cytotoxic effects of five, and the antihyperalgesic and antiedematous activities of two extracts.…”